How to combat small-font-spam.. �����ϴ� ����� ���� - �۲� - ���� ���� ..
A a recent trend in spamming �ֱ��� ���� ���й� observed in Larry Seltzer's blog and elsewhere is to use very small font size characters to create an ascii art to provide spam messages. ������ ��α� ź��� ����� �ٸ� ������ �ſ� ���� �۲� ũ�⸦ ���ڸ� ��� ��Ʈ�� ����� ���� ������ �����մϴ�.
What is interesting is that unlike the example above spammers can use legitimate email messages chosen randomly from computers they have hacked to create the ascii art. ���� ������ �� ��̰� �����Դϱ� ���иӴ� �չ����� �̸��� ������ ����� ���ֽ��ϴ� ��ǻ�Ϳ��� �������� ���õ� ��Ʈ ���� ��ŷ�� �����մϴ�. Currently filters including naive bayesian are unable to filter messages which appears as normal emails. ���� �����Ͽ� ���� ������ ��Ÿ���� ���̺꺣�̽��� ���������� ���� ������ ������ ������ϴ�.
The only way I can think of to filter such messages is to look for effective size of the fonts in the message. ���� ���� ���ִ� ������ ����� �̷��� ������ ������ �۲��� ũ�⸦ ã�� ������ ȿ���������մϴ�. And if the size is not normally humanly readable (anything smaller than 7px should be a good first guess) should be treated as spam. ���� ������ ũ��� �Ϲ������� �ΰ��� ���� ������ϴ� (�ƹ��͵� 7px���� ���� ���� ù ��° �����ؾ��մϴ�)�� �������� ó���Ǿ���մϴ�.
Any other ideas? �ٸ� ���̵��?
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March 3rd, 2005 at 10:42 pm 2005�� 3�� 3�Ͽ��� ���� 10�� 42��
Or just force your mail client to discard the html and ��rich text�� content of all mails. �ƴϸ� �׳� ���� ������ ���� Ŭ���̾�Ʈ�� ���� ����� '�����ִ� �ؽ�Ʈ'�������� ��� �������մϴ�. If someone wants to send me a html file, they can zip it up and attach it to the mail�� �� ���ϴ� ������ ���� ���, ���� �װ��� ���Ͽ� ÷�� �� ���� ��ȣ��
March 9th, 2005 at 4:01 am 2005�� 3�� 9�Ͽ��� ���� 4�� 1��
Yes, one: read emails as plain text. ��, 1 : ���� ������ �Ϲ� �ؽ�Ʈ�� �����մϴ�. It has the additional benefit of warding off many viruses. warding ��ΰ� ���� ���̷����� �߰� �������մϴ�.
March 17th, 2005 at 7:24 pm 2005�� 3�� 17�Ͽ��� ���� 7�� 24��
@Jonas and @Denis @ ���� �� �� @ ���
True. true. But you also miss many colorful messages from your friends and important newsletters etc. ���� ���� �߿��ϴ� �̽� ���� ģ���� ���� ���� �� ��ä�ο�� ���� ����
As Rabindranath Tagore (famous Bengali poet and Nobel laureate) once said in a small poem (roughly translated): �� ��� ��� ��Ʈ Ÿ�? (���� ����� ����, ���� �뺧)�� ���� �ø� �̷��� ���߽��ϴ� (�� ��) :
��We close the door to lies, truth says you have also closed the door for me�� "�츮�� ���� �ݽ��ϴ� ������, ��� ����� ���� ���� ���� �ݾҵ�"
@Jonas @ ������
I like the idea of asking friends to send zipped version of html. �� ���� ��� ����� ���� ���� ���� ���� ģ������ ������ html�մϴ�. But how will I tell all my clients ������ ��� �� ��� Ŭ���̾�Ʈ�� ���